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[function] Automatic boost::ref for functors?
by Robert Dailey 12 Nov '08

12 Nov '08

Hi, I noticed in the Boost.Function documentation here that it explains how to pass a reference to a function object into a boost::function. Is there a way to make boost::function automatically take the reference of any function object it is given? For example: boost::function<void (int)> f; f = MyFunctionObject(); // This is an implicit: f = boost::cref( MyFunctionObject() ); Help is appreciated!

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Bind and overloaded operators in Visual Studio 2008
by Benjamin Swerts 12 Nov '08

12 Nov '08

Hello everyone, This is my first post to this list so apologies in advance for all the rules I will be breaking. I have a problem using overloaded operators in Visual Studio 2008 SP1 (no feature pack installed) with Boost version 1.36.0. The following code works perfectly in Visual Studio 2005: ////////// #include <algorithm> #include <functional> #include <vector> struct Foo { Foo(unsigned int first, unsigned int second) : first_(first), second_(second){}; unsigned int first_; unsigned int second_; }; int main(int, char*) { std::vector<Foo> v(10, Foo(1, 2)); const unsigned int test = 1; std::find_if(v.begin(), v.end(), std::tr1::bind( std::equal_to<unsigned int>(), std::tr1::bind(&Foo::first_, std::tr1::placeholders::_1), test)); std::find_if(v.begin(), v.end(), std::tr1::bind( &Foo::first_, std::tr1::placeholders::_1 ) == test ); return 0; } ////////// The 2 find_if calls have the exact same behaviour. If I compile this with 2008, I get the following errors for the second find_if call: .\main.cpp(19) : error C2784: 'bool std::tr1::operator ==(std::tr1::_Unutterable,const std::tr1::function<_Fty> &)' : could not deduce template argument for 'const std::tr1::function<_Fty> &' from 'const unsigned int' C:\Program Files\Microsoft Visual Studio 9.0\VC\include\../include/functional(1100) : see declaration of 'std::tr1::operator ==' .\main.cpp(19) : error C2784: 'bool std::tr1::operator ==(const std::tr1::function<_Fty> &,std::tr1::_Unutterable)' : could not deduce template argument for 'const std::tr1::function<_Fty> &' from 'std::tr1::_Bind<_Ret,_BindN>' with [ _Ret=std::tr1::_Notforced, _BindN=std::tr1::_Bind1,std::tr1::_Ph<1>> ] C:\Program Files\Microsoft Visual Studio 9.0\VC\include\../include/functional(1094) : see declaration of 'std::tr1::operator ==' .\main.cpp(19) : error C2784: 'bool std::tr1::operator ==(const std::tr1::shared_ptr<_Ty> &,const std::tr1::shared_ptr<_Ty2> &)' : could not deduce template argument for 'const std::tr1::shared_ptr<_Ty> &' from 'std::tr1::_Bind<_Ret,_BindN>' with [ _Ret=std::tr1::_Notforced, _BindN=std::tr1::_Bind1,std::tr1::_Ph<1>> ] C:\Program Files\Microsoft Visual Studio 9.0\VC\include\../include/memory(1598) : see declaration of 'std::tr1::operator ==' .\main.cpp(19) : error C2676: binary '==' : 'std::tr1::_Bind<_Ret,_BindN>' does not define this operator or a conversion to a type acceptable to the predefined operator with [ _Ret=std::tr1::_Notforced, _BindN=std::tr1::_Bind1,std::tr1::_Ph<1>> ] I have honestly no idea what I should do to fix this. Mailing list and google searches turned up nothing so any help would be much appreciated. TIA, Ben ------------------------- Ben Swerts Software engineer ICOS Vision Systems NV -------------------------

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Multidimensional distributions in the math toolkit?
by jesseperla＠gmail.com 12 Nov '08

12 Nov '08

Hi, I realize that it isn't in the released version, but has any thinking or progress been made on multidimensional distributions extending the math toolkit distributions? I would love to have a bi-normal, bi-lognormal, and a discrete 2-dim Markov distribution? Thanks, Jesse

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boost timer with sleep
by Andre Paim Lemos 12 Nov '08

12 Nov '08

The following code: #include <iostream> #include <boost/timer.hpp> #include <unistd.h> int main() { boost::timer t; sleep(1); std::cout << t.elapsed() << std::endl; t.restart(); sleep(3); std::cout << t.elapsed() << std::endl; return(0); } Returns (compiled with gcc 4.2.4 on Ubuntu Linux 8.04 using boost 1.36): andre@andre-desktop:~/test$ ./timer_test 0 0 Is this result expected? Why? There is another timer implementation that works with sleep? []'s Andre Paim Lemos

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I have a crash when I included serialization in my Mixed C++ project
by Raj Prasan 12 Nov '08

12 Nov '08

I had a project using both native and CLR code C++.Net. I added serialization to it. Its just crashing. I checked RTTI IS enabled.. I had this problem earlier. I had split the serialization function to both .h and .cpp files. Then it disappered when I wrote it in the class declaration in the .h file. But after I did the same to all the classes (almost 20) that needed serialization. It compiles fine, but crashes even before starting.. Debug information ============= //below the msg box that appears --------------------------- Microsoft Visual C++ Debug Library --------------------------- Debug Assertion Failed! Program: g:\Development\R50\Debug\New Rapid Vision.exe File: f:\dd\vctools\crt_bld\self_x86\crt\src\dbgheap.c Line: 1511 Expression: _CrtIsValidHeapPointer(pUserData) For information on how your program can cause an assertion failure, see the Visual C++ documentation on asserts. (Press Retry to debug the application) --------------------------- Abort Retry Ignore --------------------------- //stack trace msvcr90d.dll!_msize_dbg(void * pUserData=0xdc9ffce0, int nBlockUse=2) Line 1511 + 0x30 bytes C++ msvcr90d.dll!_dllonexit_nolock(int (void)* func=0xdcd983c0, void (void)* * * pbegin=0x0012eecc, void (void)* * * pend=0x0012eec4) Line 295 + 0xd bytes C msvcr90d.dll!__dllonexit(int (void)* func=0xdcd983c0, void (void)* * * pbegin=0x0012eecc, void (void)* * * pend=0x0012eec4) Line 273 + 0x11 bytes C New Rapid Vision.exe!_onexit(int (void)* func=0x00467f20) Line 110 + 0x1b bytes C New Rapid Vision.exe!atexit(void (void)* func=0x00467f20) Line 127 + 0x9 bytes C New Rapid Vision.exe!boost::serialization::singleton<boost::archive::detail::`anonymous namespace'::oserializer_map<boost::archive::xml_oarchive> >::get_instance() Line 104 + 0x34 bytes C++ New Rapid Vision.exe!`dynamic initializer for 'boost::serialization::singleton<boost::archive::detail::`anonymous namespace'::oserializer_map<boost::archive::xml_oarchive> >::instance''() Line 121 + 0x8 bytes C++ [Managed to Native Transition] New Rapid Vision.exe!_initterm(void** pfbegin = 0x004683C4, void pfend = ) Line 130 C++ New Rapid Vision.exe!<CrtImplementationDetails>::LanguageSupport::InitializeNative() Line 534 C++ New Rapid Vision.exe!<CrtImplementationDetails>::LanguageSupport::_Initialize() Line 657 C++ New Rapid Vision.exe!<CrtImplementationDetails>::LanguageSupport::Initialize() Line 855 C++ New Rapid Vision.exe!?.cctor@@$$FYMXXZ() Line 901 + 0x9 bytes C++ [Frames below may be incorrect and/or missing, no symbols loaded for mscorwks.dll] kernel32.dll!7c83971e() kernel32.dll!7c809a69() kernel32.dll!7c83971e() kernel32.dll!7c809a69() mscoree.dll!7900b1b3() kernel32.dll!7c816fd7() -- With best Regards Rajavanya S Twitter me @ https://twitter.com/quakeboy I Blog @ http://www.techtola.com Call me @ 9916-90-93-92 ---------------------------------------------------------------------------------------------- "True love is knowing a person's faults, And loving them even more for them."

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Re: [Boost-users] [graph] predecessor_recorder and VertexList=listS
by M. Siebeneicher 12 Nov '08

12 Nov '08

Hello Andrew, thank you for your suggestions. Unfortunately I still have compile problems. I tried both ways, indexing by bundled properties and by using an external map. Inside the call of breadth_first_search(...) both ways end with the same compiler error (partially in german) : boost_1_35_0\boost\graph\visitors.hpp(160): error C2664: 'void put<std::allocator<_Ty>::value_type,Vertex>(T * ,ptrdiff_t,const V & )': Konvertierung des Parameters 2 von 'boost::adjacency_list_traits<OutEdgeListS,VertexListS,DirectedS>::vertex_descriptor ' in 'ptrdiff_t' nicht möglich with [ _Ty=boost::detail::adj_list_gen<boost::adjacency_list<boost::listS,boost::listS,boost::bidirectionalS,boost::property<boost::vertex_distance_t,unsigned int,de::audi::scenetree::VertexContainer>,GeoTrafo::cPose>,boost::listS,boost::listS,boost::bidirectionalS,boost::detail::retag_property_list<boost::vertex_bundle_t,boost::property<boost::vertex_distance_t,unsigned int,de::audi::scenetree::VertexContainer>>::type,boost::detail::retag_property_list<boost::edge_bundle_t,GeoTrafo::cPose>::type,boost::no_property,boost::listS>::config::vertex_ptr , Vertex=boost::adjacency_list_traits<boost::listS,boost::listS,boost::bidirectionalS>::vertex_descriptor, T=std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::listS,boost::listS,boost::bidirectionalS,boost::property<boost::vertex_distance_t,unsigned int,de::audi::scenetree::VertexContainer>,GeoTrafo::cPose>,boost::listS,boost::listS,boost::bidirectionalS,boost::detail::retag_property_list<boost::vertex_bundle_t,boost::property<boost::vertex_distance_t,unsigned int,de::audi::scenetree::VertexContainer>>::type,boost::detail::retag_property_list<boost::edge_bundle_t,GeoTrafo::cPose>::type,boost::no_property,boost::listS>::config::vertex_ptr >::value_type, V=boost::adjacency_list_traits<boost::listS,boost::listS,boost::bidirectionalS>::vertex_descriptor ] and [ OutEdgeListS=boost::listS, VertexListS=boost::listS, DirectedS=boost::bidirectionalS ] Diese Konvertierung erfordert einen reinterpret_cast-Operator oder eine Typumwandlung im C- oder Funktionsformat For example index and property map definition with bundled property: typedef unsigned int VertexID; class SCENETREELIB_API VertexContainer { public: VertexID m_idVertex; } typedef property_map<BGLGraph, VertexID VertexContainer::*>::type IndexMap; // Build the property map IndexMap im = get(&VertexContainer::m_idVertex, graphIn); std::vector<BGLVertexDescriptor> p(num_vertices(graphIn)); Any further suggestions? greetz Manuel -- Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

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using boost with Visual Studio 2005
by Natalie Happenhofer 12 Nov '08

12 Nov '08

Hi! I need to use boost with Microsoft Visual Studio C++ 5.0, but I get the error D:\Boost\boost_1_36_0\boost/config/compiler/visualc.hpp(186) : fatal error C1189: #error : "Compiler not supported or configured - please reconfigure" Is there any possibility that it might work if I changed the configure files for boost? If so, Which file do I have to alter and how? If not.. I need to use boost\multi_array, is there any older version of boost which works for my Visual Studio 5.0 and includes the multi_array class? I´d be very grateful for advice, thx, Natalie Happenhofer _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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[boost-users][bind, signal] binding a weak_ptr?
by Igor R 12 Nov '08

12 Nov '08

Hello, When using shared_ptr, we usually take an advantage of weak_ptr to break the "cycles". But sometimes the "forth connection" between the objects is by means of shared_ptr, while the "back connection" is by means of signal-slot connection. Like this: shared_ptr<Class1> o1; shared_ptr<Class2> o2; o1->someSignal_->connect(bind(&Class2::responder, o2)); // besides, o2 has a shared_ptr to o1 I'd like this signal-slot to be "weak", i.e. instead of "bind(&Class2::responder, o2)" I wish it could be "bind(&Class2::responder, weak_ptr(o2))" - which is illegal. Of course, I can define (and connect to the signal) a wrapping functor that would store a weak_ptr to the wrapped object, and would try to lock it in operator(). But probably boost already have some off-the-shelf solution for this issue? Thanks!

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[BGL] brandes betweenness vs networkx
by Matthew Galati 12 Nov '08

12 Nov '08

What is the rationale behind division by 2 for the undirected Brandes calcuation? Also, can someone show me how to get the weighted version of brandes? The following code calculates the unweighted version. #include "boost/graph/adjacency_list.hpp" #include "boost/graph/graph_utility.hpp" #include "boost/graph/betweenness_centrality.hpp" using namespace boost; int main(int argc, char * argv[]){ const int N = 6; typedef property < edge_weight_t, double > WeightMap; typedef property < vertex_centrality_t, double > CentralityMap; typedef adjacency_list<vecS, vecS, undirectedS, CentralityMap, WeightMap> UndirectedGraph; UndirectedGraph g(N); add_edge(0, 1, 3, g); add_edge(0, 2, 2, g); add_edge(0, 3, 6, g); add_edge(0, 4, 4, g); add_edge(1, 3, 5, g); add_edge(1, 5, 5, g); add_edge(2, 4, 1, g); add_edge(3, 4, 2, g); add_edge(3, 5, 1, g); add_edge(4, 5, 4, g); print_graph(g); brandes_betweenness_centrality(g, get(vertex_centrality,g), get(edge_weight, g) ); boost::property_map<UndirectedGraph, vertex_centrality_t>::type b = get(vertex_centrality, g); graph_traits < UndirectedGraph >::vertex_iterator vi, vi_end; for (tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi) { printf("BRANDES centr[%d] = %g\n", *vi, b[*vi]); } } Boost/graph gives the following: 0 <--> 1 2 3 4 1 <--> 0 3 5 2 <--> 0 4 3 <--> 0 1 4 5 4 <--> 0 2 3 5 5 <--> 1 3 4 I AM HERE dispatch2 CALLING UNWEIGHTED BRANDES centr[0] = 1.83333 BRANDES centr[1] = 0.333333 BRANDES centr[2] = 0 BRANDES centr[3] = 0.666667 BRANDES centr[4] = 1.83333 BRANDES centr[5] = 0.333333 While networkx gives: http://networkx.lanl.gov/reference/generated/networkx.betweenness_centralit… {0: 3.6666666666666665, 1: 0.66666666666666663, 2: 0.0, 3: 1.3333333333333333, 4: 3.6666666666666661, 5: 0.66666666666666663} So, boost is exactly 1/2 of networkx's solution. Is one version wrong? Or is this some kind of convention that boost and networkx disagree on? Thanks, Matt

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Fw: [signals2][review] The review of the signals2library (formerly thread_safe_signals) begins today, Nov 1st
by vicente.botet 12 Nov '08

12 Nov '08

forwarding to boost(a)list.boost.org ----- Original Message ----- From: "Frank Mori Hess" <frank.hess(a)nist.gov> To: <boost-users(a)lists.boost.org> Sent: Monday, November 10, 2008 4:25 PM Subject: Re: [Boost-users] [signals2][review] The review of the signals2library (formerly thread_safe_signals) begins today, Nov 1st > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Monday 10 November 2008 05:30 am, Fabio Fracassi wrote: >> * Automatic connection management: >> This is great, even if it wasn't required for thread safety reasons, I >> prefer using shared_ptr based connection tracking over boost::trackable, >> since it enables me to track (and thus safely use) 3d party classes. > > One issue that has occurred to me with the shared_ptr use, is it requires > the > use of boost::shared_ptr. So, if someone's program is instead always > using > std::shared_ptr for example, that could be a bit of an annoyance. One > solution would be to make it support anything that provides the > shared_ptr/weak_ptr interface by making slotN::track() a template and > doing > some type erasure inside the library. Unfortunately, neither the > shared_ptr > or weak_ptr interface provides a typedef for it's associated > weak_ptr/shared_ptr type, and I would need to get both the weak_ptr and > shared_ptr type from the single argument passed to slotN::track(). So, > I'd > have to add some template traits classes that could determine if a class > is a > shared_ptr or weak_ptr, and the type of its associated weak_ptr or > shared_ptr. I could provide specializations of the traits classes for the > shared_ptr/weak_ptr implementations I know about (boost, std, tr1, etc), > otherwise the user would have to provide a specialization. > > The other option would be to add yet another template parameter to the > signal > class for the shared_ptr type, but it has too many parameters already. > >> I haven't done a comparison, but the Docu seems to be mostly the same as >> the original signals. Thus for the usecases that are documentated there >> its high quality, but I miss the same for the new features: >> >> * I miss tutorial quality examples for some of the new features: >> ** Howto use boost::threads with signals2 >> ** Howto use postconstructors/predestructors (and what for?) >> ** An example using signal::extended_slot_type > > Yes, it seems clear I'm not going to get away with the minimal porting job > I > did on the Boost.Signals documentation. Speaking of the postconstructor > stuff, I'm not entirely happy with the deconstruct_ptr interface. Maybe > I'd > like it better if it looked more like make_shared/allocate_shared and had > a > helper for declaring it as a friend, as has been recently proposed on > boost-devel for make/allocate_shared. > >> * The class reference pages (e.g. >> doc/html/boost/signals2/connection.html) are missing from the TOC > > That's just how boostbook does it. The TOC links to the header synopsis, > and > the class names in the header synopsis link to the class reference pages. > I > do remember having a little trouble navigating through it myself initially > though. > >> * Do the portable syntax examples need to be supported (... so >> prominently)? Maybe they could be moved to an appendix? > > I agree they don't, although most of the other additions to the docs > people > have been asking for would seem to take precedence. > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > > iD8DBQFJGFJu5vihyNWuA4URAsUpAJ0TVggC9K9Zy76p1AxtfnxA1VomsgCeL1Z8 > TrXkG8+WbKkBDS7SiUF+0+Y= > =zb8l > -----END PGP SIGNATURE----- > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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